Spring biased check valve for pipe branches

ABSTRACT

Non-return valve for positioning in a pipe socket and having a flap member rotatable around a shaft. The shaft is arranged in a plane at a given distance from the plane of the flap, whereby the flap in an open position is passed circumfluently by the medium flowing through the valve.

United States Patent Nordin et al.

[451 Dec. 12, 1972 SPRING BIASED CHECK VALVE FOR PIPE BRANCHESInventors: Lars-Erik Reinhold Nordin, Taby;

Lars William Anshelm Miillerfors, Sundbyberg, both of Sweden Assignee:Stenberg-Elygt AB, Solna, Sweden Filfid! INC. 31, 1969 Appl. No.:889,496

Foreign Application Priority Data Jan. 10, 1969 Sweden ..319/69 US. Cl..137/512, 137/527.4 Int. Cl ..,...Fl6k 15/03 Field of Search ..137/606,527, 527.4, 527.8,

References Cited UNITED STATES PATENTS Jahrstorfer ..137/51 2} 10/1935McGuffin ..137/606 2,268,806 l/1942 Curtis ..137/527 I 3,009,475 ll/l96lRichterkessing.... 137/512 5 3,023,771 3/1962 Hinds ..137/527 3,072,141'1/1963 Wheeler .137/512 1 3,074,427 l/1963 Wheeler ..137/512 13,172,424 3/1965 Stillwagon ..137/527.4

Primary Examiner-Martin P. Schwadron Assistant Examiner-William H.Wright 7 Attorney-Sughrue, Rothwell, Mion, Zinn & Macpeak [5 7 ABSTRACTNon return valve for positioning in a pipe socket and having a flapmember rotatable around a shaft. The shaft is arranged in a plane at agiven distance from the plane of the flap, whereby the flap in an openposition is passed circumfluently by the medium flowing through thevalve.

6 Claims, 2 Drawing Figures PATENTED BED 1 2 I972 SHEET 1 [IF 2 PATENTEDDEC 1 2 m2 SHEET 2 BF 2 Fig.2

BACKGROUND OF THE INVENTION l. Field of the Invention The inventionrelates to a non-return valve embodying a flap rotatably arranged in apipe socket, valve housing or the like, and'especially to thearrangement of the rotating shaft of the flap.

2. Description of the Prior Art In twin pumps, for example, a flap valveis usually used which alternately closes one of two inlets and at thesame time opens the other. Such valves, however, give rise to disturbingnoise when they change from one to the other position. r i

In order to eliminate such disturbing noise, attempts have been made tointroduce devices for damping of theimpact which arises when the flapchanges from one position to another. The seatings, for example, havebeen provided with a packing of flexible material, e.g., rubber, butdifficulties have arisen in getting these packings to-remain inposition. Attempts have also been made to enclose the flaps entirely inrubber, which has led to some damping of the noise, but in valvesintended for example for use in hot water systems the rubber quicklyages and its silencingeffect thus disappears after some time. 1

The method of arranging a flap valve for each inlet in order to avoidnoise is also known. In this case the valves are spring-loaded in such away that they open against spring pressure. Change-over from one of thetwo pumps of the twin pump to the other is effected by shutting downthe'operating pump, after which both pumps are kept shut-down for amoment so that the open valve has time to close.

Practical tests have shown, however, that valves of this kind must befairly heavily spring-loaded in order definitely to close when changingfrom one pump to another.This requires a fairly large force to keep thevalve open, which is done under the influence of the flowing medium.Especially in large installations large annual losses are incurred inthis way.

SUMMARY OF THE INVENTION The present invention is intended to eliminatethese drawbacks and at the same time to create a non-return valve whichworks without disturbing noise. The nonreturn valve according to theinvention comprises a flap rotatably arranged in a pipe socket, valvehousing or the like, and is characterized essentially in that the axisof rotation of the flap is arranged in a plane at a certain distancefrom the plane of the flap or of a diffusion vane arranged on it, sothat the flap or diffusion vane, in a position corresponding to the openvalve, is passed circumfluently by the medium flowing through the valve.

The flap may suitably consist of a disc from which, at a certain angleto the plane of the disc, there projects at least two lugs carrying theshaft around which the flap is intended to rotate. In order that theflap may be effectively passed by the medium flowing through the valve,the lugs are arranged in a plane perpendicular to the plane of the flapand at a given angle with the plane of the flap. In this way it isachieved that every normal to the flap falls to the side of the axis ofrotation.

According to an advantageous further development of the invention twoflaps with common rotating shaft are arranged inconjunction with twinpumps and spring-loaded with a spring extending between the flaps.

From measurements of' losses through a valve according to the inventionit has appeared that the losses are reduced to about one-tenth of thoseof conventional flap valves. In larger installations for continuousoperation a reduction of the losses of this order naturally leads toconsiderable annual financial gains.

Since valve housing for the purpose in question are generally made bycasting, their dimensions cannot be kept within narrow tolerances. Thisresults in the fact, for example, that the positions of the valveseatings vary somewhat from valve housing to valve housing and, if thevalve seatings are not to be adjusted by machining, the valvesmust be sosuspended that in closed position they fit the positions of the valveseatings. This can be achieved, for example, byallowing some play in themountingof the flaps around their rotating shaft. This play, however,means that an open flap can be caused to vibrate, with disturbing noiseas a result.

According to a further development of the invention this drawback aswell is' eliminated by mounting the flaps with close fit around a sleevewhich is mounted with some play on the common shaft for theflaps.

This arrangement for mounting of the flaps means that a flap, owing tothe play between the sleeve and the common shaft for the flaps, can.close tightly against a valve seating even if the position of theseating deviates somewhat from the designed position. As one flap is tobe open when the other is closed, a certain pressure is obtainedin thevalve housing deriving from the flowing medium, so that the closed flapis held pressed against its valve seating, thereby fixing in positionthe sleeve .on which the flap is rotatably mounted with close fit. Theopen flap, which is likewise mounted on the sleeve with close fit, thusobtains fixed pivoting points, so that vibrations in the flap areprevented, and also the occurrence of disturbing noise.

The rotatable arrangement of the flaps around a sleeve has a furtheradvantage, namely in conjunction with the mounting of the, flaps in avalve housing. The flaps can in this case be'mounted on the sleeveoutside the valve housing, together with a spring, to form a unit whichis then introduced into the valve housing and secured in it by means ofva shaft passing through the sleeve. This is a far simpler operationthan that required if the flaps and spring are to be fitted separatelyin correct positions in the valve housing before the common shaft forthe flaps is inserted in position.

BRIEF DESCRIPTION OF THE DRAWINGS With reference to the attacheddrawings two embodiments of the invention will now be described.

FIG. I shows a valve housing, comprising two return valves and FIG. 2shows a cross-section through an alternative suspension of the flapsaccording to the invention.

DESCRIPTION OF PREFERRED EMBODIMENT FIG. 1 shows a valve housing 1 withtwo inlets 2, 3 and a common outlet 4 for the medium which is to flowI060I0 I 0182 through the valve housing. In the valve housing there aretwo flaps 5, 6 each having lugs 9, for carrying a shaft 7 around whichthe flaps 5 and 6 are rotatably arranged. By means of a spring 8 theflaps 5 and 6 are pressed towards their respective seating.

. lf-the pressure rises, for example, in inlet pipe 2 owing to cloggingof a pump connected to that pipe, flap 5 opens under the influence ofthe pressure from the medium in inlet 2 and against the force of thespring 8. After the flap has opened, it assumes the position 5' markedby the dotted line. In this position the flap is passed circumfluentlyby the flowing medium and assumes aposition which varies slightlyaccording to the rate of flow. When the pressure in the inlet 2 falls,in conjunction with changing from one pump to another, flap 5 closesunder the influence of spring 8, which takes place without impact andthus without generation of noise. When another pump is then put intooperation and the pressure in inlet 3 rises, flap 6 opens in a mannercorresponding to flap 5.

The reason why the losses through a valve according to the invention areconsiderably lower than through hithertoknown valves would appear to bethe fact that conventional valves are kept in open position owing to thepressure of the flowing medium on one side of the flap, the whichpressure has only a small'component in a direction perpendicular to theflap, so that a fairly large force is required to keep the flap openagainst the force of the spring. In a valve according to the invention,on the other hand, the flap is passed circumfluently by the flowingmedium and at least part of the flow losses which always arise in avalve are used to keep the flap open. There is thus an interplay betweena positive pressure on one side of the flap and a negative pressure onits other side, which keeps the flap in open position when medium flowsthrough either of inlets 2 and 3.

FIG.v 2 shows how the flaps 5 and 6 are mounted with close fit on asleeve 1 l, which in turn is mounted with a certain play 12 on thecommon shaft 7 of the flaps. When one flap 6, under the influence ofpressure from a flowing medium, is caused to assume an open position,the other flap 5 closes under the influence of spring 8. Owing to theplay 12 existing between the sleeve 1 and shaft 7 the position of flap 5can be adapted to its valve seating even if the position of the seating,owing to small imperfections in manufacture of the valve housing,deviates slightly from the intended position. Owing to the pressureexercised by the medium flowing through the valve housing on the closedflap 5, the latter, and therefore the sleeve 11, is held in a fixedposition. Thereby it is achieved that the open valve 6 which, like flap5, is rotatably mounted around the sleeve 11 with close fit, obtainsfixed pivoting points and is thus not brought into vibration.

With this arrangement of the flaps 5, 6 around a sleeve 11 an extremelyefficient and silent operating non-return valve for twin pumps isobtained.

Although the invention has been described with reference to one of itsembodiments, it can be arbitrarily varied within the scope of thefollowing claims.

What we claim is:

l. A non-return valve assembly for fluids comprising a valve housinghaving a seat and at least one conduit havir g an inlet and outletpassage;

a ap rotatably arranged in the valve housing and having a pair of lugs,the flap adapted .to seal against the valve housing seat, and

a shaft positioned in the valve housing so that it is 0 one side of thefluid flowing through the valve when the valve is in an open position,the lugs connecting the flap to the shaft and projecting perpendicularlyto a plane containing the flap a distance which is greater than aperpendicular distance from the center of the shaft to an elongation ofa plane tangential to the side of the conduit nearest the shaft in thevalve housing, so that theflap, when open, is passed circumfluently bythe fluid flowing through the valve.

2. A non-return valve as in claim 1 further including spring means onthe shaft biasing the flap to a closed position with respect to thevalve housing seat.

3. A non-return valve as in claim 2 where the plane of the flap in theclosed position is such that any perpendicular to the plane will lie onone side of the shaft.

4. A non-return valve asin claim 3 where the valve housing has two Ybranch-shaped inlet conduits with respective seats and a common outletconduit, and a second flap has a pair of lugs and is arranged to sealagainst the second conduit and seat, whereby the shaft is positionedbetween both inlet conduits in the outlet conduit and pivotably supportsthe lugs of both flaps.

5. A non-return valve as in claim 4 where each of the lugs haveover-sized diametrical bores with respect to the diameter of the shaftto permit a loose'connection with the shaft, whereby each flap when inan open position permits the fluid flowing through its respectiveconduit to flow circumferentially about the flap.

6. A one way flow valve assembly for controlling the flow of fluid fromtwo inlet conduits into a single outlet conduit comprising a Y-shapedbranched valve housing having a pair of inlet conduits and a singleoutlet conduit, the inlet conduits forming an acute angle at theirjunction;

seating means including a flap member for sealing each inlet conduit;

a shaft positioned in the outlet conduit and between each inlet conduitadjacent their junction;

a pair of lugs on each flap member having diametrically over-sized boresrelative to the shaft, the shaft positioned through the bores to permita pivotable rotation of each flap member; and

a u-shaped spring connecting each flap member to the shaft for biasingthe respective flap members to a sealed closed position, each flapmember positioned with respect to the shaft so that a plane containingthe flap member in the closed position is such that any perpendicular tothe plane will lie on the same side of the shaft as the flap member, thelugs which connect each flap member to the shaft project from the planeof the flap member, a distance which is greater than a perpendiculardistance form the center of the shaft to an elongation of a planetangential to the side of the respective inlet conduit nearest the shaftwhereby each flap member when in an open position permits the fluidflowing through the respective conduit to flow circumferentially aboutthe flap member.

1. A non-return valve assembly for fluids comprising a valve housinghaving a seat and at least one conduit having an inlet and outletpassage; a flap rotatably arranged in the valve housing and having apair of lugs, the flap adapted to seal against the valve housing seat,and a shaft positioned in the valve housing so that it is on one side ofthe fluid flowing through the valve when the valve is in an openposition, the lugs connecting the flap to the shaft and projectingperpendicularly to a plane containing the flap a distance which isgreater than a perpendicular distance from the center of the shaft to anelongation of a plane tangential to the side of the conduit nearest theshaft in the valve housing, so that the flap, when open, is passedcircumfluently by the fluid flowing through the valve.
 2. A non-returnvalve as in claim 1 further including spring means on the shaft biasingthe flap to a closed position with respect to the valve housing seat. 3.A non-return valve as in claim 2 where the plane of the flap in theclosed position is such that any perpendicular to the plane will lie onone side of the shaft.
 4. A non-return valve as in claim 3 where thevalve housing has two ''''Y'''' branch-shaped inlet conduits withrespective seats and a common outlet conduit, and a second flAp has apair of lugs and is arranged to seal against the second conduit andseat, whereby the shaft is positioned between both inlet conduits in theoutlet conduit and pivotably supports the lugs of both flaps.
 5. Anon-return valve as in claim 4 where each of the lugs have over-sizeddiametrical bores with respect to the diameter of the shaft to permit aloose connection with the shaft, whereby each flap when in an openposition permits the fluid flowing through its respective conduit toflow circumferentially about the flap.
 6. A one way flow valve assemblyfor controlling the flow of fluid from two inlet conduits into a singleoutlet conduit comprising a ''''Y''''-shaped branched valve housinghaving a pair of inlet conduits and a single outlet conduit, the inletconduits forming an acute angle at their junction; seating meansincluding a flap member for sealing each inlet conduit; a shaftpositioned in the outlet conduit and between each inlet conduit adjacenttheir junction; a pair of lugs on each flap member having diametricallyover-sized bores relative to the shaft, the shaft positioned through thebores to permit a pivotable rotation of each flap member; and a u-shapedspring connecting each flap member to the shaft for biasing therespective flap members to a sealed closed position, each flap memberpositioned with respect to the shaft so that a plane containing the flapmember in the closed position is such that any perpendicular to theplane will lie on the same side of the shaft as the flap member, thelugs which connect each flap member to the shaft project from the planeof the flap member, a distance which is greater than a perpendiculardistance form the center of the shaft to an elongation of a planetangential to the side of the respective inlet conduit nearest the shaftwhereby each flap member when in an open position permits the fluidflowing through the respective conduit to flow circumferentially aboutthe flap member.